Friction-brake foe bobbins



UNITED STATES PATENT OFFICE.

TRUMAN ESTES, OF NORTH BENNINGTON, VERMONT.

FRICTION-BRAKE FOR BOBBINS.

Specification of Letters Patent No. 30,725, dated November 27, 1860.

To all whom it may concern:

Be it known that I, TR'UMAN ESTES, of North Bennington, in the county ofBennington and State of Vermont, have invented certain new and usefulImprovements in a Self Adjusting and Regulating Brake to be applied toBobbins; and I do hereby declare the following to be a full, clear, andexact description of the construe tion and operation of the same,reference being had to the accompanying drawings, making a part of thisspecification, in which- Figure l, represents in perspective a bob binwith the self regulating brake applied to it. Fig. 2, represents avertical cross sec tion through the bobbin and brake. Fig. 3, representsa perspective View of the brake detached from the bobbin frame.

Similar letters of reference where they occur in the separate drawingsdenote like parts in all the figures.

In unwinding thread or yarns from a series of bobbins, itis next toimpossible to always keep the bobbins of uniform size, and when not sokept, the tension upon each and every thread drawn from them varies, inexactproportion to the varying of the power required to turn thebobbins-and when the series of threads are gathered together to be putinto twine, cordage, or other fabric, it is found that the uneventension upon them, makes knotty and irregular work. Besides, it is notso strong, as the threads most strained in unwinding must stand thewhole strain upon the cord or other fabric, before it reaches those mostslack, or in other words the strained strands must break before theweight can come upon the unstrained ones. Spring brakes are out of thequestion, as they are constantly varying and are not controlled by thepower re quired to turn the bobbin at all times. Turning the bobbins bymachinery that is variable, will not accomplish the end aimed atwthecompensation must be made by the thread or yarn upon the bobbin,uncontrolled by any other mechanism.

Vhen a bobbin is full, it, of course unwinds or turns much more easilythan when nearly empty, and between these two points of full and empty,the power required to turn the bobbin is constantly varying.

My object is to provide some pressure that will vary precisely with thevarying of the power required to turn `the bobbin, and this I have doneby a very simple, but reliable mechanism. f

My invention consists in applying to the yarn or thread on the bobbin,an overbalanced friction plate or arm, so arranged as to apply itsgreatest pressure against the thread when the bobbin is full, and itsleast pressure against the thread when the bobbin is nearly or quiteempty, and that varies gradually between these two points just as thepower required to turn the bobbin increases, as will be hereafterexplained.

To enable others skilled in the art to make and use my invention, I willproceed t0 describe the same wit-h reference to the drawings.

A, represents a portion of a bobbin frame, showing a bobbin B, hungtherein, in any of the usual well known ways so as to freely turn on itssupports.

C, is the self regulating friction brake. This friction brake, as moreclearly shown in Fig. 3, is made of cast or wrought metal or parts ofeach, for cheapness and durability, but may be made of other material.The rear portion a (that is to say the portion behind its journals orsupports b, b) overbalances the forward portion c, so as to keep theforward portion c, constantly against the yarn on the bobbin, and oversuiiicient surface of the thread or yarn, as not to drop into slightdepressions, and be influenced by them, instead of the general surfaceof the yarn. This forward part of the brake, may be slightly curved asshown, and if found desirable may be made of glass, bone, wood, or anyother material than metal--the rear portion a on account of the weightis better of metal. And to prevent the brake from tipping over when anempty bobbin is taken out and a full one put in, a stop CZ may bearranged to catch the rear of the brake.

Suppose the bobbin to be full-the brake will then be in the positionshown in Fig. 1 and the thread or yarn will be drawn from the top of thebobbin as shown by the red line e. In this position of course the bobbinis most easily turned as the leverage from e, to the center of thebobbin is the greatest. In this position too the overpoise, or heavypart a of the brake is nearest to a horizontal plane, and most remotefrom its fulcrum b, b, consequently is applying its greatest force uponthe arm or plate c. Now as the yarn is unwound, the overpoise or heavypart a of the brake moves in the arc of a circle drawn from the pointY), just as the arm or plate c, moves toward the center of the bobbin,until When the part c, arrives Where it is shown in dotted lines theoverpoise Will be, nearer to the fulcrum b, in a vertical line, and thushave less power upon the part c, and make less pressure on the yarn, sothat What is lost by leverage When the yarn gets down to f, iscompensated for by the lesser pressure of the arm c, When it arrives atthe position represented by dotted lines. If the part a hung immediatelybeloW the fulcrum journals b of course it Would exert no influence on cat all but just in proportion as the part a falls from a horizontal to avertical line, in the same proportion does it diminish its force upon cuntil it runs entirely out when in a vertical position. Y

It is the application of the Roman balance to the unWinding of bobbins7and Works as mathematically correct in applying variable friction tobobbins, as the Roman balance does in connection With the regulation ofsteam. It is probably the most simple and yet the most perfectcompensation for the varying leverage of yarn as it is unwound from abobbin j that has been discovered. In practice it is perfect, in givinguniform tension to any number of threads Wound from bobbins of varyingdiameters, and as such is highly valuable.

Having thus'fully described the nature and object of my invention What Iclaim therein as new and desire to secure by Letters YPatent is A selfadjusting or regulating brake C, constructed and operating substantiallyas herein described and represented, for giving an equal and propertension to threads or yarns that are being drawn olf.

TRUMAN ESTES.

Witnesses:

J. ESSEX, D. W. C. FAY.

